Polyolefin resins have versatile utility as the materials for packaging, unwoven fabrics, container, automobile or home electric appliances because of their good appearances, mechanical strength, anti-chemical properties, or suitability for packaging, and are typically melt-kneaded at about 150 to 300° C. by using an extruder to form pellets, and then they were processed into various articles, which were in many cases used for a long period of time, and the melt flow property of such pellets was adjusted according to the use of the articles, for example, by adding organic peroxides. JP2002-212347A discloses, at paragraphs 163 to 164, column 40, propylene-ethylene random copolymer resins containing, 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butyl-phenyl)propoxy]dibenz[d,f][1,3,2]dioxaphosphepin, tetrakis(2,4-di-t-butylphenyl)-[1,1-biphenyl]-4,4′-diylbisphosphonite and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane and having processing stability and coloring resistance.